package control;

import entity.Image;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.Persistence;
import javax.persistence.Query;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import utils.ServletUtil;

@WebServlet(name = "ShowImage", urlPatterns = {"/ShowImage"})
public class ShowImage extends HttpServlet {
    
    protected void processRequest(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        
        EntityManagerFactory fact = Persistence.createEntityManagerFactory("vh11i_jeePU");
        EntityManager em = fact.createEntityManager();
     
        try {
            long imageId = ServletUtil.getLong(request.getParameter("id"), -1);
            
            Query query_image = em.createNamedQuery("getImage", Image.class);
            query_image.setParameter("imageId", imageId);
            Image image = (Image) query_image.getSingleResult();
  
            ByteArrayInputStream iStream = new ByteArrayInputStream(image.getImage());
            int length = image.getImage().length;
            
            response.setContentType(image.getMimeType());
            response.setContentLength(length);

            ServletOutputStream oStream = response.getOutputStream();

            byte [] buffer = new byte[1024];
            int len; 
            while ((len = iStream.read(buffer)) != -1) {
                oStream.write(buffer, 0, len);
            }

            iStream.close();
            oStream.flush();
            oStream.close();
        }
        finally {
            em.close();
            fact.close();
        } 
    }

    // <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">
    /**
     * Handles the HTTP
     * <code>GET</code> method.
     *
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
    }

    /**
     * Handles the HTTP
     * <code>POST</code> method.
     *
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
    }

    /**
     * Returns a short description of the servlet.
     *
     * @return a String containing servlet description
     */
    @Override
    public String getServletInfo() {
        return "Short description";
    }// </editor-fold>
}
